1. Field of the Invention
The present invention relates generally to magnetic heads that are utilized with thin film hard disk data storage devices, and more particularly to the design and fabrication of helical induction coils that are utilized in the write head components of such magnetic heads.
2. Description of the Prior Art
The ongoing efforts to develop magnetic heads having increased data writing rates are impacted by the design of the induction coils that are utilized to generate the magnetic flux of the write head. While the flat, spiral induction coils of prior art magnetic heads have been adequate, the overall length of the spiral induction coil element has a relatively high resistance and/or inductance which becomes problematic at high frequencies, as well as creating unwanted magnetic head heating due to the passage of current through the relatively high resistance coil element. Additionally, the footprint of the flat spiral coil is relatively large. This large footprint poses difficulties in placing elements close together to realize large scale integration.
To solve some of these problems, helical coils have been developed. Such coils are fabricated to wrap around the magnetic pole yoke. However, fine pitch helical coils are generally more difficult to fabricate than the prior art flat spiral coils. The present invention includes a magnetic head having a helical coil and a method for fabricating the helical coil that produces a finer pitch helical coil with fewer, simple fabrication steps than the prior art helical coils.
The present invention is a magnetic head having a helical induction coil and includes hard disk drive devices that utilize the magnetic head. The helical coil is fabricated around a magnetic pole yoke in a series of process steps that include a reactive ion etch (RIE) process step which is utilized to simultaneously form vertical interconnect vias and upper helical coil member trenches. Thereafter, in a single fabrication step, such as by electroplating, the vertical interconnect lines and the upper helical coil traces are created in a single fabrication step, such that they are integrally formed. The vertical interconnect lines provide an electrical connection between outer ends of previously formed lower helical coil traces and outer ends of the integrally formed upper helical coil traces, such that a helical coil is fabricated. In the preferred embodiment, the helical coil is composed of copper.
It is an advantage of the magnetic head of the present invention that a hard disk drive incorporating the magnetic head can be more economically manufactured.
It is another advantage of the magnetic head of the present invention that it includes a fine pitch helical induction coil that is simpler and easier to fabricate.
It is a further advantage of the magnetic head of the present invention that it includes a helical induction coil that includes vertical interconnect lines and upper helical coil traces that are integrally formed.
It is yet another advantage of the magnetic head of the present invention that vertical vias and upper helical coil trenches are fabricated in a single fabrication process step, such that the fabrication of the helical coil is simplified.
It is an advantage of the fabrication method of the magnetic head of the present invention that a single fabrication step is utilized to create vertical interconnect vias and upper helical coil trenches, such that alignment problems of these components are eliminated.
It is another advantage of the fabrication method of the magnetic head of the present invention that the vertical interconnect lines and the upper helical coil traces are integrally formed in a single fabrication step, such that only one metallization step is required.
These and other features and advantages of the present invention will no doubt become apparent to those skilled in the art upon review of the following detailed description which makes reference to the several figures of the drawings.